78817866844018 has 16 divisors (see below), whose sum is σ = 122040800107776. Its totient is φ = 38137604976720.

The previous prime is 78817866844009. The next prime is 78817866844019. The reversal of 78817866844018 is 81044866871887.

It is a super-2 number, since 2×78817866844018² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78817866844019) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47101380 + ... + 48746032.

It is an arithmetic number, because the mean of its divisors is an integer number (7627550006736).

Almost surely, 2^{78817866844018} is an apocalyptic number.

78817866844018 is a deficient number, since it is larger than the sum of its proper divisors (43222933263758).

78817866844018 is a wasteful number, since it uses less digits than its factorization.

78817866844018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2417649.

The product of its (nonzero) digits is 924844032, while the sum is 76.

The spelling of 78817866844018 in words is "seventy-eight trillion, eight hundred seventeen billion, eight hundred sixty-six million, eight hundred forty-four thousand, eighteen".